The risk of carotid endarterectomy for the asymptomatic patient: an argument for prophylactic operation.

We reviewed the records of 291 asymptomatic patients who underwent 377 carotid endarterectomy operations. The study excludes endarterectomies performed simultaneously with other operations that influence morbidity as well as endarterectomies on patients with symptoms caused by contralateral carotid stenosis. Postoperatively, nine patients had a stroke but two of the nine recovered completely after reoperation. Seven patients (2% of operations) were discharged with a neurologic deficit. One patient died of a myocardial infarction. Combined strokes with residual deficit and deaths totaled eight patients (2.2% of operations). During the time of the study the indication for operation changed from greater than 60% stenosis of the carotid artery to greater than 80% stenosis. This paper argues that, based on information currently available, a surgical morbidity rate of less than 3% justifies prophylactic endarterectomy. Surgeons must audit their results to demonstrate they can perform the operation with low risk to the patient.